Compressor lubricating system



Jan. 5, 1943. R. J. WOODS ETAL 2,307,251

COMPRESSOR LUBRICATING SYSTEM Filed May 4, 1940 4 Sheets-Sheet l IR OUTAIR 11v J 4'- OIL FROM TANK 0/1 To All? PUMP grwe/wto'w ROBERT J. WOODSI CLIFFORD J. LANE 3 e/W m/m Jan. 5, 1943. R. J. WOODS ET AL 1COMPRESSOR LUBRICATING SYSTEM Filed May 4, 1940 4 Sheets-Sheet 2ROBE/FTJ. M70054 CLIFFORD J. LANE Jan. 5, 1943. R. J. WOODS ET AL2,307,251

I COMPRESSOR LUBRICATING SYSTEM 7 Filed May 4, 1940 4 sheets sheet 5FIG. 5.

3 no W5 IFOBER T J. M00054 CLIFFORD J. LANE Jan. 5, 1943. R. J. WOOD/SETAL' 2,307,251

COMPRESSOR LUBRICATING SYSTEM I Fi1ed May 4, 1940 4 Shets-Sheet 4 F/aaOIL HPOM PRESSURE SYJ'IFM 0/]. 7'0 PRESSURE SYSTEM AIR T0 O/L 70PRESSURE 8Y6.

/// 1/2 1/0 105 I07 Elm/0 R0551? T J. W000)" 4F CLIFFOED J. LANEPatented Jan. 5, 1943 ooivniaiissoa LUBRICATING SYSTEM 1mm J. Woods,Grand Island, and Clifiord .1.

Lane, Kenmore, N. Y., assignors to Bell Aircraft Corporation, of NewYork Buffalo, N. Y., a corporation Application May 4, 1940, Serial No.333,432

6 Claims.

In general, the present invention relates to lubricating systems andmore particularly has reference to systems for lubricating an aircompressor and separating the oil from the air, thereby permitting oilfree air to be delivered to the units to be operated by the compressor.While this invention is best adapted for use in aircraft such as foroperating the de-icers, starting the power plants or pumping tires, itis, of course, obvious'that its range is of broader scope.

An object of this invention is to provide in a single unit means forsupplying oil to an air compressor and then separating the oil that isdelivered by the compressor.

Another object of this invention is to provide a pump for supplying oilto an independently driven air compressor, means for separating the oilfrom the air that is delivered-by the compressor and means forpreventing the oil from mingling with the air.

Yet another object of this invention is to provide in a single unit anoil pump for supplying oil from a supply tank to an air compressor,means for separating the oil from the air that is delivered by thecompressor, means for transmitting the air to the units to be operatedand means for returning the separated oil to the supply tank.

And a further object is to provide a lubricating system for aircompressors to be used in aircraft which can be easily and cheaplymanufactured and which consists of relatively few principal workingparts.

. To accomplish the above and-other important objects, the invention ingeneral embraces the idea of providing in a unitary structure means forsupplying oil from a source of supply to an independently driven airpump, separating the oil from the air that is delivered by the pump,returning the oil to the source of supply and then transmitting the oilfree air to the units to be operated. More specifically, the inventionconsists of an oil pump which comprises reduction gearing that drivesthe air pump and also draws oil from a supply tank and forces it to theair compressor under pressure, and the pressure can be controlled by arelief valve. A second pump is formed by including a third idler gearwhich functions to return the separated oil back to the supply tank. Aseparator such as animpeller shaped disc is attached to the drive shaftof the pump and the air from the compressor enters the impeller at thecenter and is discharged at the periphery. The impeller is so formedthat the oil which separates from the air due to centrifugal forcecollects on the impeller surface and is eventually thrown ofi withoutpassing through the air stream. The air then passes out through asuitable conduit to the units to be operated, for instance, thede-icers. An air pressure relief valve may also be incorporated tocontrol the maximum pressure in the system.

In lieu of the above assembly,-the separator can be used alone and anoutside oil pressure supply may be employed. Also, it is possible tomake use of a direct drive unit and to use separate oil pumps.

In the drawings in which the same, numerals designate similar parts:

Figure 1 is a top plan view of my novel lubrieating system.

Figure 2 is a sectional view taken along'the line 2-2 of Figure 1looking in the direction of the arrows.

Figure'3 is a sectional view taken along the line 33 of Figure 2 lockingin the direction of the arrows- Figure 4 is a sectional view taken alongthe line 4-4 of Figure 2 looking in the direction of the arrows.

Figure 5 is a sectional view taken along the line 55 of Figure 2 lookingin the direction of the arrows.

Figure 6 is a front elevational view of the impeller member;

Figure 7 is a side elevational view, partly in section, of the impellershown in Figure 6.

Figure 8 is a top plan view of a modified form of my lubricating systememploying an outside oil pressure supply in lieu of the pump shown inFigures 1 to 7 inclusive.

Figure 9 is a sectional view taken along the line 9-9 of Figure 8. 7

Referring to Figures 1 and 2, it will be noted that our novel assemblycomprises a motor I (preferably electric), an oil pump, and separator 2and 3, respectively, and an air compressor 4. The oil pump and separatorcomprise a casting 5 which is so formed at its lower extremity as toprovide an oil reservoir 6. A cover .plate I is attached to thefrontface of the casting 5 by screws 8. The pump and separator housing 5is fixed to the motor] by bolts 9 and compressor 4 is secured to thepump 2 as indicatedrat Hi. It will be appreciated from the above that wehave provided in a single unit, the means for supplying the oil to thecompressor, and the device for separating the oil from the air that isdelivered by the compressor.

In Figures 2 and 5, we have shown our oil pumping means being comprisedof reduction gearing indicated generally [2. The gearing 12 includes adrive pinion l3 keyed to shaft H which is journaled in a bearing l5. Theshaft I4 is flexibly coupled as shown at I3 to stub shaft II whichlatter shaft is secured in bore l3 formed in the end of drive shaft l3of the motor I. Meshing with the teeth of the pinion l3 and mountedtherebelow is a large gear 23 carried by shaft 2| journaled in bearing22. The pinion I3 and the gear 23 serve to force the oil from the supplysource to the moving parts of the compressor 4. The shaft 2! is coupledas shown at 23 with drive shaft 24 of the compressor 4. Consequently,the pump and the compressor are driven by the motor I through thereduction gear- .Also meshing with the large gear 23 is a small idlerpinion 25 rotatably mounted on shaft 23. As will later be more fullydescribed, the small pinion 25 functions to return the separated 011back to the supply tank.

In Figures 1, 3 and 5, there is illustrated a conduit 33 connected atone end to the oil supply tank (not shown) and communicating at itsother end with an oil inlet 3! for the oil pump 2. The oil flows frominlet 3| through oil passage 32 to a point 33 adjacent the reductiongearing l2. The oil is then carried by the teeth of the drive pinion l3to point 34 which communicates with oil duct 35 that extends to the aircompressor 4 thus lubricating the working parts of the com- If the oilpressure should become too great, the oil will be forced from point 34through another .oil passage 33 which has an oil relief valve 31positioned at the end of the passage. This valve .comprises a ball 38which is held in its closed position by one end of coil spring 39, theother end of the spring bearing against the bottom of a threaded cap 40.When the oil pressure lssuflicient to overcome the action of the spring,the ball 38 will be forced from its seat and the oil will flow past thevalve and empty into oil duct 4| which is closed at its lower end by athreaded plug 42. Located substantially midway of the length of the duct4| and at approximately right angles thereto is another oil duct 43, theouter end of which is adapted to have secured thereto an oil line 44which returns to the oil supply tank. The inner end of the duct 43 ter-'minates at point 45 adjacent the gear 23 and the idler pinion 25.

In communication with the reservoir is the lower end of oil passage 46,and the upper end of the passage extends to point 41 which is adjacentthe gear 20 and the pinion 25 for returning the oil back to the tank.The passage 45 is especially advantageous in that it will keep the oillevel in the reservoir at a low point thus preventing the separator frombecoming flooded during acrobatic maneuvers.

The compressor 4 is adapted to have air admitted thereto through line53. A mixture of air and oil re-enters the pump 2 from the compressoroutlet through a conduit 5| which communicates with an enlarged bore 52formed in the pump 2. The mixture then passes into an arcuate chamber53, that is provided with a port 54 which empties into a downwardlyextending opening 55 in the cover plate I. The opening is flared at itsouter end as shown at 53 adjacent the mid point of the separator 3.

It can be seen that the separator 3 includes a disc-like member 33carried by a hub 33 which is attached to the drive shaft l3 by a pin 3|.The hub supports a plurality of radial vanes 32, and in Figure 2, itwill be noted that the outer periphery of the disc is provided with acurved surface 33 which is positioned in a circumferential recase 34formed in the outer face of cover plate I. The upper portion of therecess 34 communicates with an arcuate chamber 35 formed in the pump 2through a bore 33. A second deflector 31 is also carried by theseparator 3 and extends substantially radially to prevent the air frombeing discharged into the oil reservoir 3.

The arcuate chamber 55 empties into conduit 33 which has secured theretopipe 13 for permitting the oil free air to be delivered to the unit orunits to be operated. A second bore H communicates with the chamber 65and is positioned above the chamber, and an air relief valve 12 isdisposed above the bore H to control the maximum pressure in the system.

Referring to Figure 4, it will be seen that the cover plate I isprovided with a plurality of radial peripheral slots 53 which willpermit the oil to be thrown by the separator through centrifugal forceinto the oil reservoir 3.

As heretofore pointed out, when oil is admitted to the pump 2, the drivepinion l3 forces the oil to the point 34 from whence it flows throughpassageway 35 to the compressor. However, oil is also forced by theteeth of the gear 23 from the point 33 to the point 45 from where itflows through passage 43 and conduit 44 back to the tank. When themixture of oil and air returns from the'compressor to the pump, thismixture moves from the chamber 53 through mouth 54 to the mid point ofthe disc 53 and the oil which separates from the air due to centrifugalforce. collects on the impeller surfaces and is eventually thrownthrough the slots 53 into the reservoir 3 without passing through theairstream.

The air then goes to the chamber 35 and into the bore 33 where it isdelivered by conduit 13 to the units to be operated. The oil in thereservoir 3 moves through bore 43 to the point 41 and the teeth of thepinion 23 force the oil to the passageway 43 from whence it flows backto the oil supply tank. Consequently, there is no danger of the oil inthe reservoir flowing into the system. By the above describedarrangement it is believed readily apparent that we have provided anovel structure whereby oil can be supplied to an air compressor and themixture of oil and air returned from the compressor can be separated.Also, the gearing which constitutes the oil pumping means affords adrive for the air compressor. Furthermore, with our invention there canbe no danger of the separator being flooded due to acrobatic maneuversof the airplane, a feature which is of course most advantageous.

Referring to Figures 8 and 9, it will be noted that we have disclosed inthese flgures a modifled form of-our novel system. In this embodi mentit can be seen that we omit the oil pump 2 and employ an outside oilpressure supply.

In these figures it is apparent that the senarator is substantiallyidentical with that shown in Figures 1 to 7 with the exception that theredrive shaft ll of the motor I through shaft I33. Oil from a pressuresystem (not shown) is admitted to the compressor 4' through feed lineIIII The mixture of air and oil from' the compressor passes throughconduit I02 into the oil separator 3' as shown at I04. The mixture isthen admitted into the arcuate chamber 53' and is directed to themidpoint of the disc member 50' of the separator by the downwardlyextending aperture 55' formed in the front plate 1"of the separator. Theoil is separated-from the air by virtue of centrifugal force andcollects on the surface of the disc and is thrown through the peripheralslots i8into the oil reservoir 6.

The separated air passes through opening 66 into the arcuate chamber 65and from there is delivered to the various units to be operated by aconduit (not shown) I In view of the fact. that the roll separated fromthe air should not exceed a certain level in the reservoir 6' we providethe following assembly. A float valve designated generally I04 isdisposed in the reservoir and is pivoted to the casing at the point I05.The opposite end of the valve'carries a valve member I06 which isadapted to be fitted in the upper end of an elbow I01 which extendsthrough an opening provided in the lower wall of the reservoir. A tubesection 108 is threaded on the elbow I 01 and a springpressed ball valveI09 is disposed therein. A conduit H0 which is in communication with theoil pressure system is removably attached to the tube section I08 bymeans of fittings III and H2.

It will be appreciated that when the oil level becomes too high in thereservoir 6' the valve member I06 will be lifted from its seat and theoil will be forced past valve I09 back to the oil pressure system by theinternal air pressure in the separator. Of course this arrangement isparticularly efiicacious in that it will prevent the oil in thereservoir from exceeding a certain level thus removing the danger of theoil re-entering the system during acrobatic maneuvers of the aircraft. I7

From the above description it; is believed apparent that we haveprovided a novel system for lubricating an air compressor or the likefor use in aircraft which is highly effective and which will permit oilfree air to be delivered to the units to be operated by the compressor.Furthermore, there can be no danger of the separated oil re-mixing withthe airafter it has been separated, nor is it possible for the oil tore-enter the system while the aircraft is performing acrobaticmaneuvers. The system comprises relatively few principal working partsand can of course be easily manufactured. In addition the oil pumpingmeans and the air compressor are driven from a single prime moverthrough the gearing which forms the oil pump inthe form of device shownin Figs. 1 to 7. 7

Although we have shown and described certain connection between themumpand the compressor for operating the compressor, an impeller discsecured to the connection between the prime mover and the pump, aconduit for returning the I oil and air from the compressor to projectthem against the impeller whereby the oil and air are separated bycentrifugal force, a-conduit for re-' turning the thus separated oilto'the source, and means to deliver the air to the units to be operated.

2. In a system'of lubricating an'air compressor adapted to operate unitsin aircraft; an air compressor, a source of air'in communication with Vthe compressor, a source of oil, a prime mover,

an oil pump comprising reduction gears adapted to withdraw oil from thesource and force it to the compressor, a drive connection between theprimemover and the reduction gears for driving said reduction gears, asecond drive connection between the reduction gears and the compressorwhereby the compressor is operated, a conduit from said reduction gearsto the compressor through which the oil isadapted to be forced tolubricate the compressor, a rotatable disc attached to the'driveconnection'betwee'n the prime mover and the oil pump, a conduitextending from the air compressor to a point adjacent to the rotatabledisc for projecting the air and oil returned from the compressor againstsaid disc whereby they are separated by centrifugal force, a line forreturning the separated oil to the source, and means to deliver theseparated air to the units to be operated.

3. In a system of lubricating an air compressor adapted to operate unitsin aircraft, an air compressor, a source of air in communication withthe compressor, a source of oil, an oil pump com-.

prising reduction gears, a prime mover, a connection between the primemover and the oil pump for driving the reduction gears to withdraw oilfrom the source and force it to the compressor, a second connectionbetween the reduction gears and the compressor whereby the com pressoris operated, a conduit extending from the reduction gears to thecompressor through which the oil is forced to the compressor, animpeller disc removably fixed to the drive connection between the primemover and the oil pump, a conduit extending, from the air compressor tothe mid point of the impeller whereby the air and oil are projectedagainst the impeller and separated by centrifugal force, means carriedby the impeller for preventing the oil thus separated from re-enteringthe air, a line for returning the separated oil to the source, and

means to direct the separated air to the units to be operated.

specific embodiments of our invention, we are of course fully aware thatnumerous modifications thereof are possible by persons skilled in thisart. Our invention therefore is not to be restricted except insofar asis necessitated by the prior art and by the spirit of the annexedclaims.

We claim: r

1. In a system of lubricating an air compressor which is adapted tooperate units in aircraft, an air compressor, a source of air incommunication with the compressor, a source of oil, a prime mover, anoil pumpadapted to withdraw oil from 4. In a system of lubricating anair compressor adapted to operate units in aircraft, an air compressor,a source of air in communication with the air compressor, a source ofoil, an oil pump comprising reduction gears, a prime mover, a connectionbetween the prime mover and the oil pump for driving the reduction gearswhereby oil is withdrawn from the source and forced to the aircompressor, a second drive connection between the oil pump and thecompressor whereby the compressor is operated, a conduit leading fromthe reduction gears into the air compressor through which the oil isforced into the compressor, an impeller disc attached to the connectionthe source and force it into the compressor, a I

connection between the prime mover andthe oil pump for driving the pump,a second driving 15 between the prime mover and the'oil pump, a

conduit extending from the air compressor to a point adjacent to the midpoint of the impeller 5. In a system of lubricating an air compressoradapted to operate units in aircraft, an air compressor, a source of airin communication with the air compressor, a source of oil, an oil pumpcomprising reduction gears, a prime mover, a connection between theprime mover and the oil pump for driving the oil pump to withdraw oilfrom the source and force it to the air compressor, a second driveconnection between the oil pump and the air compressor whereby the aircompressor is operated, a conduit extending from the oil pump to the aircompressor through which the pump forces the oil into the aircompressor, an impeller disc attached to the connection between theprime mover and the oil pump, a conduit extending from the aircompressor to a point adjacent to the impeller disc for directing theair and oil into engagement with said disc whereby they are separated bycentrifugal force, means provided on said impeller disc to prevent theseparated oil from reentering the air, a line for directing the air tothe units to be operated, and a second line extending to the source ofoil, said reduction gears being adapted to force the separated oil backto the source.

6. In asystem of lubricating an air compressor adapted to operate unitsin aircraft, an air compressor, a source of air in communication withthe compressor, a source of oil, an oil pump, a prime mover, a driveconnection between the prime mover and the oil pump whereby oil iswithdrawn from the source and forced to the compressor, a second driveconnection between the oil pump and the air compressor whereby the aircompressor is operated, a conduit extending from the oil pump to the aircompressor through which the oil is forced, an impeller disc attached tothe drive connection between the prime mover and the oil pump, a conduitextending from the air compressor to a point adjacent to the impellerdisc whereby the oil and air returned from the compressor are directedagainst the impeller disc and are separated by centrifugal force, meansprovided on said impeller disc to prevent the separated oil fromreentering the air, a line to direct the air to the units to be operatedand a second line to return the oil to the source of oil.

ROBERT J. WOODS. CLIFFORD J. LANE.

